Pollution from industrial waste has been a chronic problem for chemical manufacturers, processors and refiners. It is not uncommon that during routine plant operations, equipment malfunctions, pipelines break or the process is otherwise upset causing a chemical spill. Only in the recent past has greater attention been focused on the need to quickly and efficiently contain chemical spills to prevent them from absorption into the earth with the attendant pollution problems of the adjacent aquifers which provide drinking water to nearby communities. Spills have brought other hazards mainly from the toxicity standpoint as a result of wind driven vapors adversely affecting the health of residents adjacent chemical manufacturing facilities and toxic waste sites.
As more attention was paid to the need to control spills and toxic waste and limit the impact of such spills on the surrounding communities, techniques were developed to physically contain the spilled material as well as to control poisonous or noxious vapors or odors emitted from the spilled material.
Prior techniques have involved physical containment using earthen barricades or dams. Processing units and storage facilities have been built atop concrete (coated and uncoated) mats so that spills can be channeled to a central location for treatment.
A frequent problem that occurs in sizeable spills is control of vapors or odors from the spilled material. In the past, various foams have been sprayed on the spilled material to minimize the odor and vapor problem. However, these foams broke down after a short time and had to be constantly reapplied to minimize the odor and vapor problem. Since the foam did not last very long, personnel and equipment had to be tied up adjacent the spill site, frequently for days, so that foam could constantly be reapplied as it broke down.
The need to have a stable, longlasting foam as a method of containing vapors and noxious odors is one of the problems addressed by the apparatus of the present invention. It has been determined that a foam can be chemically treated, with a stabilizing compound, so that after it is applied, the foam retains its body and turns into a gel-like substance. The gel-like substance, or stabilized foam, continues to cover the spilled material thereby effectively controlling vapors and odors for periods of time measured in days rather than minutes. In a recent experiment, stabilized foam created by the apparatus of the present invention effectively covered an approximate three acre site for approximately ninety days.
Stabilized form has another application in bomb disposal application. In the past, bomb squads have attempted to minimize the impact of a bomb, in the event it were to go off, by draping heavy mats over the bomb. This procedure has innate hazards in that the mere setting of the mats could detonate the bomb. Additionally, if a bomb is covered by other objects, such objects may have to be lifted off of the bomb before mats can be set down. Movement of objects off the bomb is another dangerous procedure which could set off the bomb. Other methods have involved spraying liquid nitrogen on the bomb so as to freeze the electrical components in the bomb thereby disarming it. However, this procedure involves transport of cumbersome equipment and handling of extremely cold liquids which can injure personnel if they come in contact with any part of the body. It was thus desirable to provide a method of encasing a bomb so as to limit the damage should the bomb go off. Using the apparatus of the present invention, stabilized foam can be quickly applied to the bomb, thereby encasing it and reducing, if not eliminating, the impact on explosion of the bomb. In one recently conducted experiment, one-sixteenth of a pound of C-4 explosive material was placed in a 3' by 3' cardboard box and the box was filled with stabilized foam. When the bomb was detonated, there was no subsequent damage to the box.
The stabilized foam is created by mixing a foam concentrate such as is presently available from the Minnesota Mining and Manufacturing Company under the name AFFF/ATC (FC 600). The stabilizer is also currently available from Minnesota Mining and Manufacturing Company under the description of FS-7000. Combinations of these two chemicals yield a stabilized foam which has been found to be beneficial in odor and vapor containment as well as an effective method in reducing or eliminating the impact from bombs frequently encountered by civilian bomb squads.
U.S. Pat. No. 4,475,821 relates generally to the field of mixing chemicals.